Adjustable Optics for Spectral Analysis of Rocket Exhaust

The figure presents additional information on the optics of the atomic-absorption-spectroscopy (AAS) system described in the preceding article. The optics include (1) a periscopic optical subsystem for access to a measurement optical axis in a plane different from that of the input and output optical axes and (2) mechanical and optoelectronic features for aligning the input and output optics.